Design and Testing of Organic Devices for Circuits

As the success and scope of organic electronics increases, there is a pressing need, and valuable potential, in ensuring the technology is available to make organic circuits that can be fully integrated. Integrating output and control technologies allows for simpler product manufacturing processes and opens up the possibilities for applications which may have in the past been restricted (such as use of flexible substrates). Due to the increased complexity of organics evolving from devices into circuitry, there are a number of factors to take into account and familiarity with all steps towards the final aim allows for more conscientious design. The aims of this study were to consider and implement a range of stages between basic organic device fabrication and analysis through to a simulation circuit design for an organic dynamic shift register. This range of investigation created a wider field of understanding, as it considers not only the final circuit design but all of the building blocks needed to reach this stage, highlighting how all of these link together. Exploring the distribution possibilities as well as a newly introduced Two Condition Theory not only proposes answers to some of the uncertainties regarding organic semiconductor transport, but provides a firm foundation for the theoretical process that leads to the parameters used in further stages of the circuit design. In order to do this, existing current models for both the disordered and polycrystalline current equations were modelled with parameters extracted from devices made within the project. As the physical restrictions in terms of the sensitivity of organic semiconductors have a crucial impact on the performance of organic circuitry, a further aim was to fabricate and understand the processing methods for organic devices using a new polycrystalline material, Lisicon™ S1200. This was necessary for producing samples that were modelled using the theoretical analysis and also gave valuable understanding of the physical considerations when completing circuit designs. This practical experience was extended to the production of devices with the aim of studying scaling implications relative to those faced in the silicon industry. Various tests were performed including the variation of semiconductor, aluminium oxide and organic dielectric thickness with the results analysed and compared. Finally, a dynamic shift register was designed and simulated for two different configurations of inverter using model parameters based upon the theoretical and practical work of earlier chapters. These were compared, and a final mask design was created incorporating all of the previous stages